Process for breaking petroleum emulsions



Patented Dec. 19, 1 933 Hairs-e r 1,940,393 PROCESS FOR BREAKING PETROLEUM Y r EMULSIONS A Melvin De e ote; st. Hollis; and Arthur F; ul hmond H i hts, m, assig p ;v Tretelite. Gompany, Websterv Groves, Mo.-, a corporation of'Missouri 7 No Drawing; ApplicatiomJamiary- 2L,- 19% '6 claims. (or; 1 ,62

They are obtainedfromproducing wells and from the bottorns ofoilstorage tanks; and are commenly referred to-as cut' oil, roily oil, emulsified oil andbottom settlings.

The object ofour invention is to provide a novel, inexpensiveandefiicient processfor sep-' arating emulsionsof the kind referred'to into their component parts of oil and water or brine. Briefly described; our-process consists in sub-' jecting' a petroleum-emulsion of' the water-in-oi-l type to the action of a t reating agent ordemulsh sifyingagent 'of a particular composition hereinafter described, thereby causing the emulsion to break downand separate into its component parts ofoil'and water-or brine, when the emul sion is permitted 1 to remain in aquiescent state after-such treatment; v v

Various; classes of' materials haveheretofore been used orsuggested as demulsifying agents" in the resolution of petroleum emulsions; suclias water softeners; modified fatty acids, hydroxy aromatics, various non-fattysulfon'ic acids;- etc. Mixtures of materials-of the kindabove mentioned havealso been used or suggested, sometimes'with improved results and sult's; Generally when" various classes of materials are I eflicient dem'uls'ii'iers; mixtures of such materials are also eificie'nt demulsifiers, provided that the materials constituting a mixture arenot incompatible, but the value or effectiveness of a mixture producedby combining a known 'demulsifier selectedfrom one classlwith'another known demulsifierselected-from a difierent class, can

easily'be determinedby simple routine chemical experimentation involvingpn'ly chemical skill or knowledge; asjdistinguished from. inventive ability. There have been instances where particular petroleum emulsions or' particular types of emul sion would not respond to treatment withtheindividual members'of a-classor classes-of demu'lsometimes with inferior re 4 sifi'ers'; or' with mixtures produced; from" selected members-of two different classes ofknowndemul sifirs'; andwh'enfsuch emulsions'are-encountered, inventive" ability "is often rg-fquired to; produce} demulsifying agent that will's'uccessfully brealsf 5'5 or treat the" emulsion under consideration.- example of a demulsifyi'rigfiagehtf of thekindilast referred to is the one described in'U'. SQPa'tje'rit No; 1,659,998; to *K 'eiser, datedfFebr'uary 21;, 1923,

which demulsifyirrgag ent consists of a mixture 63 of previously" known demuls ifiers, combined; c'ertain'specific proportions. I

The treating agent or demulsifyingagentfcoii templatedby our process isofthekindith I oomposed of a mixturejof.materials but itis 0 65 that" particular type of; mixturewhich is, clia'rac te'rizedfby great specificity both-ii the subs v 'Qe of Which it is composed," and *iii thefquantitiesfor proportions of said. substances. It consists ofor comprises'red' oil (oleic' acid); which{ isairionmodified fatty 'material, mixed." with certain specific 'substituted aromatic sulfonic" acids? or salts thereof; "A'nyor all 'fatty acids are notsuitfable;- and any or all' substituted aromatic sulto'n'ic acid'orsaltsj'arenot suitable; On-thecont'rarfyj, only red 'oil mixed' with a substituted-aromatic sulfonic acid or salt of the particular kindliere in' described and defined, contemplatedby" our invention; wefihave not found stearic acid, palrniticacid, and the'like to be suitable infreso placing red oil or' oleic' acid in the mixture even ou h they a e fiq val si fj .O l ritli ordinary prccess of soap'making; p p

The substituted aromatic sulfonic acidsgor salts employed a; part of the "mixture arelin ited to 35 those "derived from a'lcOhQIsha in g" thr'eei carbbn atomsand notfmoretha'n five carbcn-atoms;-ife3, propyl alcohol; butyl' alcohol, and "amyl" alcohol. Itis' to be understoodthat the iso'rnericalcohol's,

such'asi'normal butylj isobutyl, secondarybu'tyl,

etc-Q arecon'sidered equally satisfactory; and that the isomeric sulfonic acids, such as the alpha and beta'i are also considered-equally suitable for ourf'sp' ecific reagent} The mixtureislirnited to the alkylated naphthalerie" sul'fcnic acids} the form" of a water-soluble alkali salt The ammonium radicalisbonsidred azi'alkali along with themetals sodiuin and potassium} Ammonium l'iydroxideis justas' satisfactoryioi' neutralising the sulfonic acids l asis sodium or potassium 'h'y 10o droxide. Likewise, in the manufacture of ammonium soaps, for certain purposes,it has been found that improved products can sometimes be obtained byreplacing the ammonia with certain hydroxy amines, such as triethanolamine, which acts just the same as ammonia. We wish it to be understood that hydroxyamines which act like ammonia are considered the equivalent of the ammonium radicalv or the equivalent of an alkali metal in our invention. These substituted naphthalene sulfonic acids of the'type described represent only a small percentage of the large number of substituted polynuclear sulfonic acids. For instance substituted aromatic sulfonic acids disclosed for demulsification include those derived from the higher alkyl alcohols, as well as from aryl alcohols and aralkyl alcohols, and even cyclo alcohols. Furthermore; known demulsifiers include not only the substitution of alcohol radicals in the aromatic nucleus, but also sulfonic acids in which aldehyde residues, ketone residues, or even fatty residues are substituted in the aromatic nucleus. Then too, insead of introducingsuch residues into an aromatic nucleus, it has been suggested to introduce them into aromatic derivatives, such as hydroxy, chloro, nitro,. or car-. boxyl derivatives; It has been suggested to use this multitude of sulfonic acids in the form of calcium or magnesium salts, or'in the form of various esters or even after acylation with an amine in the manner that the sulfonyl radical substitutes'or replaces one of, the hydrogens of the selected amine. 7 We have selected a few members from this large class of aromatic substituted sulfonic acids, and as previously stated, wecontemplate only the use of the propylated or butylated or amylated naphthalene sulfonicacid in the form of a sodium, potassium, or ammonium salt. We do not contemplate the use of a reagent in which some other substituent group, such as ahydroxyl'group is present in the nucleus. Nor do we make a broad claim to mixtures of oleic acid and the particular aromatic sulfonic acid'salts herein described. Our invention isspecifically limited to a demulsifying agent containing not over 40% of water, that will show oil solubility,-as well as water solubility. Mixtures of the kind contemplated by our process must dissolve in'kerosene and produce a 20% solution, thatis, when 20 parts of the mixture is mixed with partsof ordinary kerosene- Unless the mixture shows this oil solubility, it does not appear to have any unusual effectiveness in treating petroleum emulsions. The oleic acid may be replaced in part by the sodium, potassium or ammonium salt, that is, the sodium, potassium, or ammonium 'oleate. Hydroxyamines, such as triethanolamine, are suitable substitutes for ammoniahydroxide.

In addition to having the limiting characteris.- tics previously set forth, the mixture contemplatedby our process must also show water miscibility; In other words, the mixture, in addition to showing 20% oil solubility above described, must be capable of mixing with waterto form a 5% solution or suspension of-a relatively stable type.

The most feasible way for preparing a mixture of the kind previously described is'to make a combination in which there is no more than three times as much of one type of reagent or material as-the other. In other words, if three parts of the substituted naphthalene sulfonic acid is used, one must mix therewith not less than one part ofoleicacid and not more than nine parts of oleic acid. The actual amount of oleic acid required' depends on various factors, namely, whether the product is a monoalkylated aromatic salt, or contains more than one substituting alkyl radical. there is only one 'sulfonic acid radical present, or if there is more than one. It also depends on the amount of water present,,and to some degree, on whether or not the water present contains a considerable amount of dissolved inorganic salts, such as sodium sulfate, as an inherent impurity. Solubility is also effected dependent on the base used for neutralization. Generally speaking, potassium salts or ammonium salts show greater on solubility than sodium salts. In any event,

when the mixture of the substituted aromatic sulfonic acid salt and oleic acid is prepared, if oil solubility is not suiiicient, a small amount of a base such as ammonia should then be added, so

, as to partially neutralize the oleic acid, and thus promote oilsolubility; In the majority of cases, it is best that the mixture be made in the proportion of approximately one part of the substituted aromatic sulfonic acid salt and one part of oleic acid with'subsequent neutralization.

- Ourpreierrcd,demulsifying agent is prepared in the, followingmanner: A mixture of monobutylatedand dibutylated naphthalene sulfonic acid salt is prepared in the customary manner and is neutralized with ammonia. If need be, it is concentrated so as to contain not over 40% of. water, and preferably as little as 35% U of water. It is mixed with an equal partof oleic acid and should show oil solubility when 20 parts of the mixture is shaken with 80 parts of kerosene. If said mixture does not possess such oil solubility, strong ammonium hydroxide is cautiously added with constant stirring and frequent tests made to determine the appearance of such desired oil solubility. Sometimes when such desiredoilsolubilityis obtained, it may bev desirable to continue .to add some more of the neutralizing agent, such as ammonia, .or caustic soda, or caustic potash, or. triethanolamine, as the case may be, but in no event should the addition of the neutralizing'agent be enough to eliminate the oil solubility. After the reagent has shown oil solubility of the kind described, it should be tested in water by preparing a 5% mixture. Such mixture should result in a stringy milky suspension, or even a clear solution. In otherwords,

triethanolamine, and the like. The final reagent may be used after dilution with kerosene'or carbon tetrachloride, or a water-insoluble alcohol,

such as amyl alcohol, or any other desired vehicle, which does not destroy the oil and'water solubility of the kind' previously noted. We prefer toadd 25% of kerosene to the reagent.

We believe that from the foregoing it will be apparent that our invention is not concerned with all mixtures of two classes of materials which have been preyiously used for demulsification, but on the contrary, is concerned with only a very limited class or type of mixtures that must have the characteristic or quality of both oil and water miscibility. The superiority of the reagent .or demulsifying agent contemplated by our process is based upon its ability to treat certain emulsions more. advantageously and at a somewhat lower cost than is possibl'e' withothi' ho vnqe aima 11ers; we havenot found that'our improvewge: mu'isirying'agent is of universal efie'ctiveness', arid we do not believe that awnrsiiprse'de'iheniajority" of the modified'fatty acids, sulfated fatty acid'atii, heretofore used extensively as treating agents in the resolution of petroleum emulsions. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned, but we have found that such a demulsifying agent has commercial value, as it will economically break or resolve certain oil field emulsions in a small number of cases which cannot be treated as easily and at so low a cost, with demulsifying agents heretofore available.

In practising our process, a treating agent or demulsifying agent of the kind above described may be brought in contact with the emulsion to be. treated in any of the numerous ways now employed in the treatment of petroleum emulsions of the water-in-oil type with chemical demulsifying agents, such, for example, as by introducing i the treating agent into the well in which the emulsion is produced; introducing the treating agent into a conduit through which the emulsion is flowing; introducing the treating agent into a tank in which the emulsion is stored; or introducing the treating agent into a container that holds a sludge obtained from the bottom of an oil storage tank. In some instances, it may be advisable to introduce the treating agent into a producing well in such a way that it will become mixed with water and oil that are emerging from the surrounding strata, before said water and oil enter the barrel of the well pump or the tubing up through which said water and oil flow to the surface of the ground. After treatment, the emulsion is allowed to stand in a quiescent state, usually in a settling tank, and usually at a temperature varying'from atmospheric temperature to about 200 F, so as to permit the water or brine to separate from the oil, it being preferable to keep the temperature low enough to prevent the volatilization of valuable constituents of the oil. If desired, the treated emulsion may be acted upon by one or more of the various kinds of apparatus now used in the operation of breaking petroleum emulsions, such as homogenizers, hay tanks, gun barrels, filters, centrifuges, or electrical dehydrators.

The amount of treating agent that may be required to break the emulsion may vary from approximately 1 part of treating agent to 500 parts of emulsion, up to 1 part of treating agent to 20,000 or even 30,000 parts of emulsion. The proportion depends on the type of emulsion being treated, and also upon the equipment being used, and the temperature employed. In treating exceptionally refractory emulsions of the kinds known as tank bottoms and residual pit oils, the ratio of 1:500, above referred to, may be required. In treating fresh emulsions, i. e., emul- 1'. A prdcess'for breaking etroleum emuuibzis of the water-imoil" type, which consists iz'isubjetting the emulsion to the action of an oil and water-soluble demulsifying agent containing (A) kali salt of alkylated na'piimaiefie' sulfonic acid derived from an alcohol having at least three carbon atoms and not more than five carbon atoms; and (C) a material chosen from the group consisting of oleic acid and oleic acid partially saponi fied with a substance of the class consisting of -the alkalis, ammonia and triethanolamine, the

said mixture also being characterized by the fact that the ratio of B to C is within the limits of- 1 to 3 and 3 to 1 and that the demulsifying agent will produce a 20% solution in kerosene and a 5% solution or suspension in Water.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of an oil and water-soluble demulsifying agent containing (A) not over 40% of water; (B) a water-soluble al- 3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of an oil and water-soluble demulsifying agent containing .(A) not over 40% of water; (B) a water-soluble ammonium salt of a butylated naphthalene sulfonic acid; and (C) a material chosen from the group consisting of oleic acid and oleic acid partially saponified with a substance of the class consisting of the alkalis, ammonia and triethanolamine, the said mixture also being characterized by the fact that the ratio of B to C is within the limits of 1 to 3 and 3 to 1 and that the demulsifying agent will produce a 20% solution in kerosene and a 5% solution or suspension in water.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjectingthe emulsion to the action of an oil and watersoluble demulsifying agent containing (A) not over 40% of water; (B) a water-soluble ammonium salt of a butylated naphthalene sulfonic acid; and (C) oleic acid in an amount approximately equal to the amount of B, the said mixture also being characterized by the fact that the demulsifying agent will produce a 20% solution in kerosene and a 5% solution or suspension in water.

5. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of an oil and water-soluble demulsifying agent containing (A) not over 40% of water; (B) a water-soluble ammonium salt of a butylated naphthalene sulfonic acid; and (C) oleic acid in an amount approximately equal to the amount of B and partially saponified with ammonium hydroxide, the said mixture also being characterized by the fact that the demulsifying agent will produce a 20% solution in kerosene and a 5% solution or suspension in water.

6. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of an oil and watepsoluble demulsifying agent containing (A) not over 40% of water; (B) a water-soluble ammonium salt of a butylated naphthalene sulfonic acid; and (C) oleic acid in an amount approxivmatelv equal to the amount of B, partially saponified'with ammonium hydroxide diluted with 25% 5% solution or suspen sion in water. MELVIN DE GROOTE. ARTHUR F. WIRTEL. 

